A commonly encountered problem is the need to remediate mixed wastes that have been contaminated with organic substances such as petroleum hydrocarbons, volatile organic compounds, chlorinated solvents and organo-surfactants. Mixed wastes can include soils, sludges, drill cuttings and/or sediments, also referred to herein collectively as “soils.” Thermal technologies such as thermal desorption, smoldering, pyrolysis and incineration are proven to be effective for the treatment of mixed wastes impacted with organic substances.
Most conventional thermal treatment technologies require heating of the entire mass of waste to very high temperatures (e.g., 475° C. to 1200° C.) to enhance the volatilization, degradation and/or combustion of the organic contaminants. The energy needs and costs associated with such treatment methods can therefore be prohibitively high. The presence of moisture in these wastes can reduce thermal treatment efficiency and/or further increase power needs and treatment time. Many sites are in remote locations where it may not be possible to provide sufficient power to make thermal treatment technologies viable. Consequently, most remediation practitioners choose other methods for treating impacted soils or even delay remediation of soils.
There is an ongoing need for cost-effective and energy efficient methods of treating contaminated material. In addition, there is a need for a cost-effective method incorporating waste drying.